I wanted to draw your attention to Dominick Jenkins' book, The Final Frontier. I was stunned by the perspicacity of some of the analysis of America's early empire building (although it is somewhat cursory on the anti-imperialist reflux represented by Mark Twain et al). In particular, I want to highlight a few themes that Jenkins draws out brilliantly. The first is a motivation for empire often overlooked: the need to avert the growing polarisation and class war in American society. This was recognised in the late 19th Century by Theodore Roosevelt, (whom Vidal dubbed the 'American Sissy'), and Henry Cabot Lodge, who - recognising the growing insularity of the Protestant capitalist elite, its increasing tendency to seclude itself from the rest of society in country clubs, boarding schools, fraternities and other sealed spaces, its growing ethnic exclusivity - worried about what excellent fodder this situation presented to anarchists. Industrialisation drew millions of unassimilated migrants, who were not being assimilated, while at the same time the growth of an urbanised working class and the political challenge from black workers and women contributed to the growth of a new left, comprising anarchists, populists and socialists. The populists argued that the state was serving the interests of the East Coast elite, exploiting the financial weakness of farmers and grinding down the poor. The socialists and anarchists argued that since the ruling class was visibly pursuing its own interests, the working class should certainly pursue its own interests, and to hell with purblind patriotism.

Roosevelt et al contended that to save America, a new frontier was needed: by waging wars of expansion, always with the fondest motives, always with civilisation and Christian virtue in mind, Americans would be impressed by their collective power and would "come to see themselves, as they had done in the Civil War, the Indian Wars, and in the colonization of new land, as a community of heroes engaged in a struggle upon which the future of humanity depended." Well, if that isn't American imperialist ideology to a tee. The firefighter, policeman, intrepid reporter, blue-collar bum, incorruptible union activist, brave American soldier - heroism is the supreme imperialist virtue (even if its application is cowardly, corrupt, venal, brutal, and in general as unlikely to inspire admiration as any form of human conduct).

The impression this was supposed to make on popular consciousness was immense: vice, Roosevelt argued, would be blown away like chaff once Americans had "something to think about which isn't material gain" - that is, the vice of class struggle would be whipped if American workers were occupied with fantasies of noble domination, of personal sacrifice and national supremacy. The creation of the Rough Riders when America declared war on Spain in 1898 was an early attempt to galvanise such a national feeling: it was one of three volunteer cavalries sent to fight in Cuba, putatively on the basis of liberating the island from oppressive Spanish rule. The 'classlessness' of the Rough Riders was emphasised: Bucky O'Neil, Roosevelt's "dearest comrade" was twice a Populist candidate for Congress; one sergeant was a leading Gold Democrat (a short-lived formation devoted to classical liberalism); one was a well-known socialist. In doing so, they provided an idealised 'democratic' community, representative and meritocratic, with cowboys and millionaires mingling their blood on the battlefields.

America's frontiers had been bounded to the West by the coast, to the south by the conquest of Texas, and to the north by the 1812 war. If a new frontier was sought, it was a perpetually shifting one: Cuba was taken, and so were the Philippines. In the latter, the Americans had to contend with Emilio Aguinaldo's insurgency, which fought both a convential war (initially, and to its great loss) and a guerilla war (later, and with much success). Given that the methods used to suppress the rebellion could not help but inspire outrage and disgust in an America not yet thoroughly imbued with imperialist doctrine, Roosevelt made the following pitch: "Every expansion of civilisation makes for peace ... The rule of law and order has succeeded to the rule of barbarous and bloody violence. Until the great civilised nations stepped in there was no chance of anything but bloody violence." He noted the Peace Conference at the Hague and the declining frequency of conflict between the European powers as instances of the peaceful lot of civilised nations - the Filipinos, by contrast, weren't even a nation, but a diversity of tribes and clans, and the rebels merely represented one tribe, the Tagalogs. Roosevelt compared them to the Apaches, and Aguinaldo to Sitting Bull. A long period of American rule was in order.

Now, let's take a look at the Nobel Peace Prize. Before Henry Kissinger was able to count satire among his millions of victims, Elihu Root was a recipient of that ignoble award. Under McKinley and Roosevelt, he was the US Secretary of War, then Secretary of State, then a Republican Senator. He worked in the field of international law, and worked in the Carnegie Endowment for International Peace. He served the cause of peace in the Rooseveltian sense - as an imperialist warrior - and was emphatically opposed to Wilson's early neutrality on WW1. He maintained a firm Open Door policy (and was happy to kick in a few doors). In 1907, in his role as Secretary of State, he lectured Yale University students, explaining to them their role as a future elite. The trouble afoot, he explained, was that humanity would face multiple catastrophes that only the ruling class could ward off. He explained that they must explain to Americans the absolute necessity of state involvement in civilising each quarter of life, since the "fairest and most fertile" plots had been left as wildnerness for years under no government, while "under good government, industry and comfort flourish on the most sterile soil". They should highlight the progress that modern governance had brought them, and the dependence of every aspect of modern life on good governance. What is more, they should alert fellow Americans to the fact that good governance helps them to govern themselves, providing "self control - organised capacity for the development of the race". They ought to remind people of the tyranny of the mob, that most awesome of despots: look at the Red Terror, the French Revolution, the Wat Tyler rebellion... oh, look gentlemen, and fear. Make the people afraid of themselves, by all means possible. Finally, Americans ought to understand their achievements in light of ancient Rome, which had the virtue of being both an empire and a republic.

Another early endorsement of the new frontier ideology came from Woodrow Wilson, who saw the reforming elite as the best means of cementing Americans to "the best government of the few". He wrote for The Atlantic Monthly, today one of Hitchens' favourite haunts an generally the house magazine of liberal Zionism, on the topic of 'Democracy and Efficiency'. Democracy must prove itself efficient or face "reactionary revolution", he mused. Speaking wistfully of the genocidal campaign against the Indians, he added: "Until 1900 the United States always had a frontier ... There was always space and adventure enough and to spare, to satisfy the feet of our young men ... The whole European world, which gave us our materials, has been moralised and liberalised by the striking and stupendous spectacle". Accentuating the powerful emulative force of Americans past, Wilson goes on to add that "Our interests must march forward, altruists though we are; other nations must stand off, and do not seek to stay us."

In another article, 'The Ideals of America', Wilson argues that the "spirit of the old days is not dead", being "the very principle of life in a nation alive and quick in every fibre". He argued that the 1812 war, in which America sought to expand into Canada, was the true war of independence. And he tried to ward off the ideological offensive of the Anti-Imperialist League, who argued that conquest and colonisation was precisely what the colonists had rebelled against. He urged fellow Americans to understand that their capacity for self-government had been developed under the long subordination to King George, who taught them respect for authority and the common good, obedience to the law and patience with slow change. They could come to understand this "preparatory discipline" again if they experienced the introduction of democracy to the Philippines, whose luckless inhabitants would need years in stars n stripes flecked training diapers before moving on to self-government.

Not only would it be necessary to create a new American public of course - the moulding a new imperial state as crucial. This required, according to Roosevelt: a drastic expansion in the power of the executive; the reduction of representative government to professional administration in support of the executive; the use of political science to perfect technocratic methods; the use of academic institutions to make the system more meritocratic. Wilson was not a democrat in the sense that he thought the common masses should have a say in government (ie, not a democrat in any meaningful sense). He perceived the masses as governed by irrational sentiment, and argued that "Representative government has had its long life and excellent development, not in order that common opinion, the opinion of the street, might prevail, but in order that the best opinion, the opinion generated by the best possible methods of general counsel, might rule in affairs". Indeed, universal suffrage was liable to put an end to republican liberty (capitalism) as far as he was concerned. He didn't like it one bit.

Well, Wilson and the blueblood reformers weren't alone. The drive to empire was propelled by another social group whose status was becoming uncertain: the military elite. The Military Services Institute, formed in 1878, was to represent and coordinate the interests and knowledge disciplines of what Jenkins calls the 'military progressives', those who were persuaded of the need for a professionalised officer corps, a standing army, military academies... the trouble was, they depended on Congress for appropriations but could not point to a single enemy that raised the need for a large standing army. What they sought to do therefore was to offer the state control over warmaking, using the sciences to derive laws akin to those provided by mathematics and mechanics. Far from being dangerous to liberty, they could show with copious example, standing armies were essential to it. What is more, by understanding the mechanics of conflict better, they could minimise the risk of war, as well as the risks of warmaking. It was necessary, of course, to engage in the inflation of threats (or the invention of them), since America's railway system, industry and agricultural surpluses all favoured its rapid defense in the event of an attempted invasion. General Emory Upton advanced some unique arguments: first, that America's military successes were impaired by excessive human and financial waste, a matter which would be remedied through science and professionalisation; and second, that there was a great propensity for internal commotion - Shay's Rebellion, the Whisky Rebellion, the Great Rebellion, the Rail Roads riots of 1877 - which would need to be crushed before it became a nation-wide insurgency so that democracy could prevail. Others wondered how much the immigrant communities really valued American interests, particularly given a conflcit with the societies from which they had emigrated. Further, it was argued that America's growing transportation and commerce internationally would make it more vulnerable to attack, and that to assert her rights as a trading nation, it would be essential to have the military werewithal to resist rival intimidation. And they offered the instance of China, a great civilisation, plundered and humbled by a cluster of imperial locusts. New York's growing financial prominence might well surrender to foreign conquest as the Yangzi Delta's manufacturing dominance once had.

While the patrician reformers converged with the military progressives in their empire-building tendencies, the crucial gulf between them was how they perceived military service itself. The reformers tended toward a romanticised view of volunteer warriors, and of the army as a place to emulate American heroes past. The military progressives knew that it could never be thus. They sought an army capable of defeating a large European or Asian power, which meant conscription - men would be forced to fight by drill, propaganda and the threat of the firing squad. What is more, the military leadership knew as well as the reformers did that the main examples of heroism past were less salutary than anyone would publicly admit: the war against the south having been won through the prodigious use of terror against the civilian population. There was one way, and one way alone, to get around this: if the ordinary soldier could not be a hero, the commander could. The future of romantic combat lay in the charismatic power of commanding officers.

I think in all of this, you have the essential ingredients for the transition from an increasingly challenged, polarised and crisis-ridden republic to an empire. There was a sustained resistance to this transition, and the coordination of sectional and class interests was not an easy or harmonious one. It was pulled off in the end by the skilful manipulation of Europe's endemic and fatal crises by FDR. The resistance of the Anti Imperialist League that saw the Democratic Party adopt Filipino independence as part of its programme in 1900 was continued in various forms by the American left at least until World War II. This is to its immense credit: European social democracy never knew anything like this, and is still imbued with imperial habits of thinking. There was not, contrary to popular mythology, ubiquitous hostility to the Vietnam War on the British left. The Suez affair did generate opposition, but not only on the Left. Indeed, the main source of opposition on the Left came from Atlanticists like Hugh Gaitskell, who insisted that it was unthinkable that a British government would again embarrass its new American overlords. It might have seemed that the final victory of the imperial state over the American left had been accomplished during the anticommunists crusades of the 1950s, following which Kennedy's 'New Frontier' successfully welded imperialist expansion with mild social democracy. But the racial oppressiveness of American society, the returning crisis of capitalism and growing hostility to aggression against Vietnam, opened a new generation to the arguments of Third World anti-imperialist movements. It forced at least a section of the American public to begin to understand non-white freedom fighters as brothers and sisters. In the prolonged interval of defeat since then there has been plenty of resuscitation, refinement and fortification of imperial ideology. Plenty of heroes too. But since the growing rapaciousness of the capitalist system, its immiseration of most American workers over the last thirty years and its declension into a more and more violent and desperate condition, is alienating larger numbers of people from the society, dissuading would-be patriots in large numbers, and since it has not and cannot be displaced through renewed imperialist expansion, it isn't too optimistic to imagine that the imperial state has not run out of challengers.